The University of California brought in a record $1.64 billion in private donations in the last year, surpassing $1.5 billion for the third time in a row, according to an annual report that will be presented to the UC Regents on Wednesday.

The number of donors — nearly 300,000 — is also rising, said Daniel Dooley, senior vice president for external relations.

About 30 percent of the contributions went to research.

The growing importance of donors in the 10-campus university system is reflected in the number of endowed chairs, or professorships: 81 in 1980, compared to 1,700 today.

The giving is mostly tied to specific projects, though, making it unlikely that private donations will ease the system’s reliance on public funding, Dooley said.